Bicycle rear sprocket assembly and bicycle rear sprocket

Abstract

A bicycle rear sprocket comprises a sprocket support member, a first attachment portion, and a second attachment portion. The sprocket support member comprises a first support member and a second support member. The first support member includes a first radially outer portion and a first radially inner portion. The second support member includes a second radially outer portion and a second radially inner portion. The first support member faces the second support member in the axial direction to define an axial gap provided between the first support member and the second support member in the axial direction. The first radially outer portion of the first support member is configured to be attached to the second radially outer portion of the second support member via a bicycle sprocket positioned between the first attachment portion and the second attachment portion in the axial direction.

What is claimed is: 
     
       1. A bicycle rear sprocket assembly comprising:
 a sprocket support member rotatable about a rotational center axis, the sprocket support member having a first axial side and a second axial side opposite to the first axial side in an axial direction parallel to the rotational center axis, the sprocket support member comprising:
 a first support member including a first radially outer portion and a first radially inner portion, the first support member at least partly constituting the first axial side; and 
 a second support member including a second radially outer portion and a second radially inner portion, the second support member at least partly constituting the second axial side, the first support member facing the second support member in the axial direction to define an axial gap provided between the first support member and the second support member in the axial direction, the axial gap being an open space that extends from at least a portion of the first support member to at least a portion of the second support member in the axial direction; 
 
 a first attachment portion provided at the first radially outer portion of the first support member; 
 a second attachment portion provided at the second radially outer portion of the second support member; and 
 the first radially outer portion of the first support member being configured to be attached to the second radially outer portion of the second support member via a bicycle sprocket positioned between the first attachment portion and the second attachment portion in the axial direction. 
 
     
     
       2. The bicycle rear sprocket assembly according to  claim 1 , wherein
 the first radially outer portion is spaced apart from the second radially outer portion in the axial direction. 
 
     
     
       3. The bicycle rear sprocket assembly according to  claim 1 , wherein
 the first attachment portion is spaced apart from the second attachment portion in the axial direction. 
 
     
     
       4. The bicycle rear sprocket assembly according to  claim 1 , wherein
 the first attachment portion includes a first surface, 
 the second attachment portion includes a second surface, and 
 the first surface faces the second surface in the axial direction. 
 
     
     
       5. The bicycle rear sprocket assembly according to  claim 4 , wherein
 the first surface is in contact with the bicycle sprocket in a state where the bicycle sprocket is attached to the first attachment portion, and 
 the second surface is in contact with the bicycle sprocket in a state where the bicycle sprocket is attached to the second attachment portion. 
 
     
     
       6. The bicycle rear sprocket assembly according to  claim 1 , further comprising:
 a hub engagement portion with which a bicycle hub assembly is to be engaged. 
 
     
     
       7. The bicycle rear sprocket assembly according to  claim 6 , wherein
 the hub engagement portion is a separate member from at least one of the first radially inner portion of the first support member and the second radially inner portion of the second support member. 
 
     
     
       8. The bicycle rear sprocket assembly according to  claim 7 , wherein
 the first radially inner portion is configured to be attached to the second radially inner portion via the hub engagement portion. 
 
     
     
       9. The bicycle rear sprocket assembly according to  claim 6 , wherein
 the hub engagement portion is provided integrally with at least one of the first radially inner portion of the first support member and the second radially inner portion of the second support member as a single unitary member, and 
 the hub engagement portion is directly attached to an other of the at least one of the first radially inner portion of the first support member and the second radially inner portion of the second support member. 
 
     
     
       10. A bicycle rear sprocket assembly comprising:
 a sprocket support member rotatable about a rotational center axis, the sprocket support member having a first axial side and a second axial side opposite to the first axial side in an axial direction parallel to the rotational center axis, the sprocket support member comprising:
 a first support member including a first radially outer portion and a first radially inner portion, the first support member at least partly constituting the first axial side; and 
 a second support member including a second radially outer portion and a second radially inner portion, the second support member at least partly constituting the second axial side, the first support member facing the second support member in the axial direction to define an axial gap provided between the first support member and the second support member in the axial direction; 
 
 a first attachment portion provided at the first radially outer portion of the first support member; 
 a second attachment portion provided at the second radially outer portion of the second support member; and 
 the first radially outer portion of the first support member being configured to be attached to the second radially outer portion of the second support member via a bicycle sprocket positioned between the first attachment portion and the second attachment portion in the axial direction, wherein 
 the first radially outer portion includes first radially outer parts, 
 the second radially outer portion includes second radially outer parts, 
 each of the first radially outer parts includes a first attachment hole, 
 each of the second radially outer parts includes a second attachment hole, and 
 a rivet extends through the first attachment hole and the second attachment hole. 
 
     
     
       11. A bicycle rear sprocket assembly comprising:
 a sprocket support member rotatable about a rotational center axis, the sprocket support member having a first axial side and a second axial side opposite to the first axial side in an axial direction parallel to the rotational center axis, the sprocket support member comprising:
 a first support member including a first radially outer portion and a first radially inner portion, the first support member at least partly constituting the first axial side; and 
 a second support member including a second radially outer portion and a second radially inner portion, the second support member at least partly constituting the second axial side, the first support member facing the second support member in the axial direction to define an axial gap provided between the first support member and the second support member in the axial direction; 
 
 a first attachment portion provided at the first radially outer portion of the first support member; 
 a second attachment portion provided at the second radially outer portion of the second support member; and 
 a hub engagement portion with which a bicycle hub assembly is to be engaged, wherein 
 the first radially outer portion of the first support member being configured to be attached to the second radially outer portion of the second support member via a bicycle sprocket positioned between the first attachment portion and the second attachment portion in the axial direction, and 
 the hub engagement portion is provided integrally with at least one of the first radially inner portion of the first support member and the second radially inner portion of the second support member as a single unitary member.